#2199 Definite integral not obtained -infinite loop-

[Cervera]

The "activation":

-4.0*'integrate(2*t^2*(0.35-1.1*t^2)*sin(1.51*t)^2/cos(1.51*t)^3+t^2*(0.35-1.1*t^2)/cos(1.51*t),t,0.0,0.5);
ev(%,nouns);

..... a LOT of time after: a final result:
Maxima encountered a Lisp error:
Error in PROGN [or a callee]: The storage for CONS is exhausted.
Currently, 20996 pages are allocated...
...

build_info();
Maxima version: 5.24.0
Maxima build date: 17:5 5/16/2011
Host type: i686-pc-linux-gnu
Lisp implementation type: GNU Common Lisp (GCL)
Lisp implementation version: GCL 2.6.7

......
problem was identical under the 5.22 version in the stable squeeze's Debian distribution

[Raymond Toy]

With cmucl, I don't get the error about cons storage exhausted, but it does run for a long time. Long enough that I stopped it.

But it looks like you just want a numerical value for the integral. In that case, use a numerical method like quad_qags, or romberg, or some other method to give you a number.

[Cervera]

The problem is associated to a search for a minimun, where the definite expression is an intermediate in a local search: the general expresion is indefinite and the failure in the search in produced because the algorithm can't obtain a float result to the definite integral. So, the definite integral failure is a precondition to the minimum search failure.

Cheers